What You Wanted to Know About Smart Homes

Three experts weigh in on standards and security

31 December 2015

The Institute’s December special report is dedicated to that once-futuristic vision of a smart home that anticipates our needs, keeps us healthy, and saves us money. IEEE is working to make this vision a reality. Readers wanted to know more about the implementation, standards, and security for smart homes. Here to answer your questions are three experts in the field.

Bill Ash is strategic technology program director of the IEEE Standards Association, in Piscataway, N.J.; Sri Chandrasekaran is the director of standards and technology, based in the IEEE India office, in Bangalore, and IEEE Fellow Tariq Samad is a 30-year veteran at Honeywell, a global manufacturer of automation and control systems, in Minneapolis.

Q: For me to purchase smart-home technologies they must be easy to use, fully integrated and, most importantly, secure. What standards as well as current or future technologies support these requirements?

ASH: There are many different technologies that already exist and will exist in the future. So I will pick one area to use as an example: smart energy. In this area there is an IEEE standard called IEEE 2030.5 Smart Energy Profile. It uses widely adopted standards like IP, RESTful HTTP—software architecture style for the World Wide Web, and Web security standard TLS 1.2 HTTPS to build its profile.

These standards allow flexibility on devices that can be used to interact with energy systems. They also allow the consumer, like yourself, to have an interface on existing devices such as smartphones, tablets, and computers.

CHANDRASEKARAN: There are multiple standards that address smart-home technologies such as the suite of communication standards IEEE 802 for wireless, IEEE 277 and IEEE 1701 for smart metering, and IEEE P2413 for the Internet of Things. Security is an integral aspect for these standards. Revisions to the IEEE 802 suite have addressed security aspects for specific applications. IEEE P2413 has a sub-working group that focuses on security and privacy aspects.

Q: Implementing smart-home devices into existing homes can be a challenge due to modifying existing wiring installations—not to mention the intrusion on other devices and poor aesthetics. Do wireless sensor networks address these problems? What concerns do WSNs raise? 

CHANDRASEKARAN: Not all smart-home devices require changes or modifications to existing wiring. Typically such modifications are done within the backend of the instrument, which is not exposed externally.

SAMAD: Yes, wireless sensor networks do address these problems and a majority of the smart-home devices are being built as a part of a wireless sensor network. Honeywell’s thermostats, security systems, and related sensors used in smoke and motion detectors, and automated doors, lights, and windows, are all networked wirelessly.

The biggest challenge that wireless devices face is there are so many standards that are available and suitable for different devices, and they all need to work together. For example, door contact sensors need to be tiny to be mounted on doors so they need a lightweight wireless protocol, which can communicate with smaller batteries and security panels. This requires communication to take place from a door sensor, alert authorities over a cellular system, and stream a camera feed over Wi-Fi to the homeowner.

Q: With streaming video, security cameras, and text messages already taking up many available Wi-Fi channels, how will smart home devices avoid being disrupted?

SAMAD: Luckily the bandwidth available for homes has not been saturated. So while streaming video, security cameras, and text messages are taking up a lot of bandwidth on Wi-Fi, there is still enough bandwidth available to transport the application payloads from the sensors in smart homes. Wi-Fi itself has frequency diversity—2.4 and 5.8 gigahertz—as well as quality-of-service schemes that ensure “important” messages are prioritized.

Furthermore, some of the sensors in a smart home will continue to operate in communication channels, such as Bluetooth, that can co-exist with Wi-Fi communications. 

CHANDRASEKARAN: As more data-intensive applications are driven through the router, they will impact some of the applications, depending on the router’s bandwidth. Typically, channel selections in a router are done to avoid noise and interference. The quality of experience will be driven by the bandwidth. Some applications allow you to manage or adjust settings for bandwidth restrictions that make it possible for them to perform slightly better when data-intensive applications, such as streaming movies, are also running in parallel.

ASH: We are seeing devices use multi-frequency bands like routers based on the IEEE 802.11ac standard that use both 2.4GHz and 5GHz frequency bands. Another solution is the technology in IEEE 1905.1 Standard for a Convergent Digital Home Network for Heterogeneous Technologies. This standard addresses convergence of networking technology for the home, allowing devices to change between networking technologies to optimized bandwidth and data rates for improved quality of service.

Q: The U.S. National Institutes of Health estimates that 10 percent of the U.S. population has some type of medical implant. I have one myself, which experiences interference when crossing devices such as security gated facilities and even electric and hybrid cars. Can smart-home devices potentially interfere with medical implants and, if so, will this be taken into consideration when designing and implementing them?

CHANDRASEKARAN: A lot of advanced research is happening in the area of electromagnetic interference with implanted medical devices for devices operating in the sub-GHz range. Government regulations mandate devices to work within the presence of electromagnetic radiation—known as EMI (electro-magnetic immunity). For safety and critical devices the EMI levels are typically much higher because they need to operate without malfunctioning in an environment of higher EM interference. However these stricter guidelines might not apply to implanted medical devices not considered “critical.”

SAMAD: Almost all smart-home devices are being built on communication protocols that permeate a modern home, whether they are smart Internet-connected devices or not. The operating frequency of Wi-Fi signals (2.4 Ghz) is especially attractive for device makers since it is an “open” frequency band worldwide. From that perspective, the smart devices should not cause any interference with medical implants if those implants do not experience interference in such places as coffee shops and airports.

Q: As an engineer, I don’t like the concept of a black box for smart homes. I would instead like to have an open box that I could tinker with and configure myself. Can you point me to resources to help me build my own?

SAMAD: With application program interfaces (APIs) and mashups—which use content from more than one source to create a new service—being published for smart-home devices, tinkering with them is becoming easier. These devices are seldom black boxes.

With the varied number of standards out there, engineers like us are well equipped to tinker and provide interplay among devices even if they don’t talk the same protocol. We can build hardware-based playgrounds with Raspberry Pi’s—a tiny computer that is easy to program—or software-based playgrounds on smartphones and PCs. Portals and apps like If This Then That (IFTTT) are including a multitude of these APIs for people to play with and even publish their own code. Others are evolving and establishing IoT frameworks, including Allseen, HomeKit, Smartthings, ZigBee, and Zwave.

Q: What do you foresee will become the standard protocol for home automation in the future?

ASH: I am not sure we will see a single protocol as there are many technologies and protocols being used today, depending on applications and use cases. For those looking at a vertical application I would hope they would standardize protocols and not use proprietary solutions as this would end up raising the cost for the consumer in the long run.  

SAMAD: This famous quote from computer scientist Andrew S. Tanenbaum’s, “The nice thing about standards is that you have so many to choose from,” certainly applies to smart-home devices and the Internet of Things. Thanks to him and other pioneers of the Internet there is one standard that most home-automation devices are converging to at the networking layer: the Internet protocol, particularly IPv6.

Security and privacy are other important aspects of these smart-home device standards. Almost all standards are converging toward the use of certificates and public key infrastructure-based authentication and encryption.

Soumitri Kolavennu, Samad’s colleague at Honeywell, helped with answering these questions.

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